Composition capable of free radical polymerization resulting in shockproof organic glass materials

ABSTRACT

A radically polymerizable composition comprising: 
         a first component A comprising at least an oligomer having at least two radically polymerizable functions and the homopolymer of which has a glass transition temperature (T g ) lower than 50° C., such a component being able to result through polymerization in a (co)polymer having a glass transition temperature (T g ) equal to or lower than 50° C., preferably equal to or lower than 0° C. and more preferably ranging from −50° C. to −10C, said oligomer accounting for more than 15%, preferably at least 20% of the total weight of the polymerizable monomers present in the composition; and a second component B comprising at least a (meth)acrylic monomer having at least one H link promoting group, such a (meth)acrylic monomer accounting for at least 15% of the total weight of the polymerizable monomers and oligomers present in the composition when such a monomer is a methacrylic monomer and at least 35% of the total weight of such polymerizable monomers and oligomers present in the composition when such a monomer is an acrylic monomer.

The invention generally relates to thermally photopolymerizable and/or polymerizable compositions, depending on the primer type being used for the reaction, resulting in transparent lenses, more particularly ophthalmic lenses, with a good shock resistance.

One of the best known organic lenses used for its excellent shock resistance properties is bisphenol-A polycarbonate, commonly referred to as PC, and the derivates thereof. Such a lens, being a thermoplastic material, is fully satisfactory for the wearer and can be produced at economical costs through injection by using injection moulding machines, perfectly well adapted to mass production.

When these are so-called prescription lenses, i.e. manufactured on demand depending on the correction to be applied to the lens wearer's eyesight, a previously injected semi-finished lens is being used, one face thereof already having its definitive geometry and the second face being then surfaced, followed by polishing operations using appropriate tools.

Polyurethane-polyurea based shock resistant material lenses have recently been marketed under the trade name TRIVEX®. The method for obtaining such lenses is disclosed in U.S. Pat. No. 6,127,505.

Other materials from the same chemical family, but incorporating sulphur to increase the refractive index, are disclosed in International Patent Applications WO 01/36.507 and WO 01/36.508.

Such materials are obtained through polycondensation by means of a tricky to implement method.

European Patent Application EP 1,035,142 discloses the polymerization of an acrylic copolymeric material for obtaining ophthalmic items comprising polymerisation of at least one α,β-ethylenically unsaturated carboxylic acid and of at least one aryl(meth)acrylate monomer in the presence of a cross-linking agent. The cross-linking agent, optionally accounting for 0.5 to 15% in weight of the total weight of the monomers present in the composition, more particularly comprises ethyleneglycol dimethacrylate, diethyleneglycol dimethacrylate, polyethyleneglycol dimethacrylate, allyl methacrylate, 1,3-propanediol dimethacrylate, allyl methacrylate, 1,6-hexanediol dimethacrylate, 1,3-butanediol dimethacrylate, 1,4-butanediol dimethacrylate, as well as divinyl compounds including divinyl hydrocarbons and divinyl benzene.

The examples in said Patent Application only mention the use, as a cross-linking agent, of ethyleneglycol dimethacrylate or 1,3-butanediol dimethacrylate.

The article by Robert A. SCOTT and Nicolas A. PEPPAS <<Compositional effects on network structure of highly cross-linked copolymers of PEG-containing multiacrylates with acrylic acid >> discloses a photopolymerisable composition containing PEG 400 diacrylate and 23.6% in weight of acrylic acid.

It would therefore be desirable to provide a radically polymerizable composition, more particularly through photopolymerization, resulting in a polymeric material having a high shock resistance, good thermomechanical properties, a low water absorbency and able to be used for manufacturing transparent substrates, in particular optical items such as ophthalmic lenses.

The above-mentioned technical problems are overcome according to the present invention by a radically polymerizable composition comprising:

-   -   a first component A comprising at least an oligomer bearing at         least two radically polymerizable functions and the homopolymer         of which has a glass transition temperature (T_(g)) lower than         50° C., such a component A being able to bring through         polymerization to a polymer having a glass transition         temperature (T_(g))<50° C., preferably equal to or lower than         0° C. and preferably ranging from −50° C. to −10° C., the         oligomer of the component A accounting for more than 15%,         preferably at least 20% of the total weight of the polymerizable         species present in the composition; and     -   a second component B comprising at least one (meth)acrylic         monomer having at least one H link promoting group, such a         (meth)acrylic monomer accounting for at least 15% of the total         weight of the polymerizable species present in the composition         when such a monomer is a methacrylic monomer and at least 35% of         the total weight of such polymerizable species when such a         monomer is an acrylic monomer.

Preferably, the oligomer of component A is a difunctional compound.

Generally, the oligomer of component A has a number average molecular mass ranging from 100 to 5,000, preferably from 200 to 4000, more preferably from 300 to 2,000 g.mol⁻¹.

The oligomer of the first component A is preferably selected amongst poly(alkylene)glycols di(meth)acrylates, polyethoxy bisphenol-A di(meth)acrylate, dithio(meth)acrylate oligomers and urethane di(meth)acrylates, thiourethane di(meth)acrylates and di(meth)acrylate polysulfides.

The preferred polyalkyleneglycol di(meth)acrylates are polyethyleneglycol and polypropyleneglycol di(meth)acrylates, more particularly polypropyleneglycol di(meth)acrylates and most particularly, polypropyleneglycol dimethacrylates.

The preferred dimethacrylate oligomer is a polypropyleneglycol dimethacrylate with a number average molecular mass of about 530 g.mol⁻¹ (PPG 400 DMA) marketed under the designation SR644OP by CRAY VALLEY Corporation.

Such polyethylene- or polypropyleneglycol di(meth)acrylate oligomers suitable for the present invention can be represented by the following formula:

wherein R¹ and R² represent H or CH₃, A represents a divalent moiety with the formula:

where m₁, m₂ and m₃ are each an integer ranging from 4 to 20.

When several oligomers (I) are used admixed together, a mean value can be defined: $\overset{\_}{m} = {\sum\limits_{m = 4}^{20}{X_{m} \cdot m}}$ wherein X_(m) is the weight ratio of the oligomer (I) for which A comprises m ethylene- or propyleneglycol patterns in its chain based on the total weight of the oligomers with formula (I) of the blend.

When as the first component A of the invention, commercial products are used that are already oligomer blends, such a value m is easily obtained performing a HPLC analysis of the blend t calculating the report: $X_{m} = \frac{S_{m}}{S_{total}}$ where S_(m) represents the surface of the peak corresponding to the monomer (I) comprising m propyleneglycol patterns in the divalent moiety A, and S_(total) represents the total surface of all the peaks corresponding to the monomers (I) for which m ranges from 4 to 20.

According to the invention, blends of several polymers (I) are preferably used for which the mean value {overscore (m)} such as defined hereinabove ranges from 5 to 10, preferably from 6 to 9.

However, it is possible to use blends of several oligomers (I) for which the mean value is higher than 20 and preferably ranges from 30 to 40. Calculating the mean value occurs as hereinabove, but for all the oligometric fractions, including of course for the oligomers (I) for which the value {overscore (m)} is higher than 20. A commercially available oligomer exists for A=propoxy and {overscore (m)}=32.

Still preferably, the monomers (I) have a branched structure, i.e. the divalent moiety A represents:

m₃ having the meaning as previously indicated.

The monomers (I) are commercially available from CRAY VALLEY Corporation under the commercial designations SR⁶⁴⁴OP, CD644OP and from SHIN NAKAMURA Corporation under the commercial designation 9PG and from the UCB Corporation under the commercial designation PPG400.

SR6440P is a blend of several monomers (I) the central pattern is as follows:

with m₃ as an integer having values ranging from 3 to 10 according to the following mass ratios: m₃ = 3  2% m₃ = 4  8% m₃ = 5 14% m₃ = 6 20% m₃ = 7 27% m₃ = 8 19% m₃ = 9  9% m₃ = 10  1% with a mean value {overscore (m)}₃=6.6.

Another di(meth)acrylate oligomer class suitable for the component A of the composition according to the invention includes the polyalkoxy (preferably ethoxy or propoxy) bisphenol-A dimethacrylates having from 10 to 80 alkoxy patterns (in mean value).

Amongst such bisphenol-A di(meth)acrylate compounds are to be mentioned the compounds represented by formula (II):

where R¹ and R² represent, independently from each other, H or CH₃, X represents —(CH₂—CH₂—O)—, —(CH₂—CH₂—CH₂—O)— or —(CH₂—CHCH₃—O)—, preferably —(CH₂—CH₂—O)—,-and n₁+n₂ has a mean value ranging from 10 to 50, preferably from 10 to 40.

Preferred compounds represented by the above-mentioned formula are those for which R¹=R²=CH₃, X=CH₂CH₂O—, and n₁+n₂=10 or n₁+n₂=30.

Preferred ethoxy bisphenol-A di(meth)acrylate oligomers are bisphenol-A dimethacrylate with 30 ethoxy patterns (BPA30EODMA) marketed under the designations BPE-1300N by SHIN NAKAMURA CHEMICALS and SR 9036 by CRAY VALLEY Corporation, bisphenol-A dimethacrylate with 32 propoxy patterns, bisphenol-A diacrylate with 32 propoxy patterns and bisphenol-A diacrylate with 16 propoxy patterns.

The most preferred bisphenol-A oligomer is BPA30EODMA.

The oligomer of component A of the compositions according to the invention could also be a di[thio(meth)acrylate], i.e. an oligomeric compound containing two functions:

more particularly, a dithiomethacrylate represented by the formula:

where n is an integer ranging from 1 to 10, or a blend of such dithiomethacrylates.

The oligomer of the component A could also be an urethane di(meth)acrylate. In particular are to be mentioned the aliphatic urethane diacrylates marketed by CRAY VALLEY Corporation under the designations CN934, 935, 965, 963, 966, 967, 981 and by UCB Corporation under the designations EBECRYL 230, 244, 245, 270, 284, 285, 4830, 4835, and 8800 and the aromatic urethane diacrylates marketed by CRAY VALLEY Corporation under the designations CN 970, 972, 973 and 976 and UCB Corporation under the designations EBECRYL 210, 215 and 4244.

When the oligomer of component A is an urethane di(meth)acrylate, high amounts of components B are preferably used (at least 40% in weight of the polymerizable species present in the composition).

Component A of the compositions of the invention could additionally comprise at least one other comonomer, being not an oligomer, comprising at least one radically polymerizable function and, preferably, two radically polymerizable functions.

The preferred comonomers for component A are mono- or di(meth)acrylate comonomers such as alkyl(meth)acrylates such as methyl(meth)acrylate and ethyl(meth)acrylate; cycloalkyl(meth)acrylates such as cycloethyl(meth)acrylate and dicyclopentyl(meth)acrylate; aryl(meth)acrylates such as phenyl(meth)acrylate, benzyl(meth)acrylate; naphthyl(meth)acrylates; phenoxyalkyl(meth)acrylates such as phenoxyethyl(meth)acrylate and phenoxybutyl(meth)acrylate; alkyleneglycol dimethacrylates such as ethyleneglycol di(meth)acrylate and propyleneglycol di(meth)acrylate.

Other comonomers include vinyl or polyvinyl compounds as well as allyl or polyallyl compounds such as divinylbenzene.

However, selecting such comonomers should occur so that the first component A brings, through polymerization, to a polymer or copolymer with a glass transition temperature Tg equal to or lower than 50° C.

The second component B is preferably a monofunctional compound and more particularly a compound represented by the formula: CH₂═C(R)—Z—Z′  (IV) wherein R represents H or CH₃, Z represents a single covalent link or a spacer group.

Z is preferably a divalent hydrocarbon chain, optionally interrupted by one or more heteroatoms, preferably selected amongst O, S, N or by one or more groups as follows:

by one or more divalent groups selected amongst:

-   —NH—CO—NH— -   —NHCOO— -   —NHCOS— -   —NHCSS—.

Still preferably, the hydrocarbon chain is a short chain and comprises from 1 to 10 carbon atoms and more preferably from 1 to 6 carbon atoms.

As an example, the spacer group Z could be a polyether, polyester, polyurethane, polyurea, polythiourethane group.

Z′ is a monovalent short chain, preferably comprising from 1 to 10 carbon atoms, and more preferably from 1 to 6 carbon atoms and includes at least one H link promoting group selected amongst the groups:

-   —COOH -   —OH -   —CONHR′ -   —NHCONHR″ -   —NHCOOR′″ -   —NHCOSR^(iv) -   —NHR^(v)     where R′, R″, R′″, R^(iv), R^(v) represent, independently from one     another, H or an alkyl with from 1 to 10 carbon atoms or aryl with     from 6 to 10 carbon atoms.

The alkyl group could be itself aliphatic or cycloaliphatic.

Preferably, the alkyl group represents represents CH₃.

Preferably, Z′ represents a H link promoting group selected amongst COOH, OH and CONHR′ groups, preferably a COOH group.

Preferably, R is CH₃.

The H link promoting group in the compound with formula IV could also be, on its own, a carbonyl function and/or a tertiary amine function. In such a case, both those functions interact with the above-mentioned functions for Z′ and all comprising a polar link of the X—H type (X═O, S, N . . . ) for forming hydrogen links. The carbonyl and tertiary amine functions could therefore be used as a complement of the above-mentioned H link promoting functions.

The preferred monofunctional monomers having hydrogen link precursor groups are methacrylic acid (AMA), acrylic acid (AA) and (meth)acrylic monoesters of carboxylic diacids such as mono-2-(methacryloyloxy)ethylsuccinate (MA succinate) represented by the formula: CH₂═C(CH₃)CO₂CH₂CH₂O₂CCH₂CH₂CH₂CO₂H  (a) and mono-2-(methacryloyloxy)ethylphthalate (MA phthalate) represented by the formula: 2—[CH₂═C(CH₃)CO₂CH₂CH₂O₂C]C₆H₄CO₂H  (b)

Preferably, component B is methacrylic acid.

Still preferably, components A and B are only methacrylic compounds.

The compositions according to the invention also comprise a polymerization priming system. The polymerization priming system could comprise one or more thermal or photochemical polymerization primers. Such primers are well known in the art and any conventional primer could be used. Amongst such thermal polymerization primers useful in the present invention are to be mentioned peroxides such as benzoyl peroxide, cyclohexyle peroxydicarbonate and isopropyl peroxydicarbonate.

Amongst the photoprimers are to be mentioned, more particularly, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 1-hydroxycyclo-hexylephenylketone, 2,2-dimethoxy-1,2-diphenylethan-1-one and alkyl benzoyl ethers.

In general, primers are used in a proportion ranging from 0.01 to 5% in weight based on the total weight of the polymerizable monomers contained in the composition.

The polymerizable compositions according to the invention could also comprise additives conventionally used in polymerizable compositions for moulding optic or ophthalmic items, in particular glass lenses and lenses, in the conventional proportions, i.e. release agents, inhibitors, dyes, UV absorbers, perfumes, deodorizing agents, antioxidants, anti-yellowing agents and photochromic compounds.

The use of H link promoting component B has the advantage to stiffen the very flexible network formed by component A, without, however, introducing a too high cross-linking density which would be detrimental to the shock resistance of the final material. Thus, the polymerized materials according to the invention have the required thermo-mechanical properties, i.e. a good stiffness at 25° C., which is the use temperature for the lenses, and at 100° C. which is the temperature reached at various steps of the method for manufacturing the glass and upon subsequent processings (coloration, polishing). The materials obtained from the compositions according to the invention have an elastic modulus (E′) at 100° C. of at least 40 MPa, preferably 100 MPa and more preferably of at least 120 MPa, or most preferably 150 MPa.

Preferably, the compositions according to the invention are photopolymerisable compositions and the materials obtained through the polymerization of compositions according to the invention are preferably organic lenses obtained through conventional moulding, preferably through photopolymerization.

As previously indicated, the lens could be a semi-finished lens, that is that one face thereof is still to be surfaced into its final geometry, but obviously, the method could equally apply to manufacturing a finished lens, i.e. comprising both optical faces at the required geometry at the end of the moulding operation.

A finished lens can thereby be obtained at the shortest notice through photopolymerization using conventional photopolymerization devices, in a much easier way to implement and to control than in the case of a polycondensation.

The resulting lenses have an excellent shock resistance as well as a very low water absorption.

The following examples illustrate the present invention. In the examples, unless otherwise indicated, all the percentages and parts are in weight.

EXAMPLE 1

60 g of BPA30EODMA are mixed with 40 g of methacrylic acid at room temperature. Mixing is performed, 0.1 g of CGI 819® is added (phosphine oxide photoprimer from Ciba). The composition is obtained in a room with a controlled lighting in a smoky glass vial.

The thus prepared composition is cast into a mould in two mineral glass parts previously cleaned with soda, parallely assembled by means of a Bamier adhesive tape and two millimetre apart.

Casting occurs as follows:

-   -   the composition is taken out using a sterile syringe (20 ml);     -   the adhesive tape is partially dismantled so as to create an         opening;     -   the tip of the syringe is inserted into the opening;     -   the composition is injected into the mould; and     -   the adhesive tape is replaced in order to sealingly close the         mould.

The filled mould is then put in a photochemical polymerization oven comprising two UV prima lamps (mercury lamps) arranged on both sides at equal distance of the mould parts, the mould receiving from each lamp an illumination of approximately 40 milliwatt for 30 seconds.

The infrared measurements allow to follow the conversion of double (meth)acrylic links as a function of the UV irradiation time. After 30 seconds of irradiation, the conversion is completed.

After polymerization, the adhesive tape is removed. The lenses are then released and then checked with an arc lamp.

A final annealing operation at 120° C. allows to bring the polymerization to completion and to release the residual constraints of the resulting substrate.

The results are indicated in table 1 hereinbelow.

COMPARATIVE EXAMPLES C1 AND EXAMPLES 2 to 4

Example 1 is repeated varying the methacrylic acid and BPA 30EODMA proportions. The proportions of the starting components as well as the results are indicated in table 1 hereinbelow.

Comparative example C1 comprises BPA30EODMA as polymerizable monomer. TABLE I C1 EX1 EX2 EX3 EX4 Polymerizable composition (liquid) BPA 30EODMA (%) 100 60 50 45 70 AMA (%) 0 40 50 55 30 Release agent¹ (%) 0 0 0.1 0.1 0.1 UV absorber² (%) 0 0 0.07 0 0 Photopolymerization primer³ (%) 0.1% 0.1% 0.1% 0.1% 0.1% n_(D) (25° C.) 1.491 1.470 1.464 1.460 1.456 Density — — 1.08 1.06 — Solid polymerized material n_(e) (25° C.) — 1.516 1.518 1.515 1.517 ν_(e) (25° C.) — 48 49 55 53 Density 1.16 1.23 1.25 1.25 1.26 E′ at 25° C. (MPa) — 1,600 3,560 4,000 4,500 E′ at 100° C. (MPa) — 140 1,300 1,600 2,200 Tg (° C.) −30 40 — 160 >160 ¹ZELECUN (lubricant from DUPONT CHEMICALS) ²UV 5411: 2-(2-hydroxy-5′-t-octylphenyl)benzotriazole from AMERICAN CYANAMID Corporation ³CGI 819 ® from CIBA GEIGY Corporation (The amounts of release agent, UV absorber and photopolymerization primer are indicated in % based on 100 parts in weight of components A and B.)

The starting molecule BPA30EODMA (BPE-1300N from Shin Nakamura Chemical) is a bifunctional compound, the homopolymer of which is very flexible (Tg=−30° C. measured through differential scanning calorimetry).

Stiffening of the network is illustrated by the increasing values of E′ (25° C.), E′ (100° C.) and Tg upon the introduction of methacrylic acid. From 50% of methacrylic acid, the obtained Tg is higher than 150° C., which is particularly high for an acrylic thermo-hardened network.

The density of the solid material is relatively high, illustrating the intensity of interactions of the hydrogen link type.

Introducing methacrylic acid into the system limits the network water uptake. However, introducing high rates of highly polar acidic function should result in an increased hydrophilic character. Such behaviour shows that acidic links strongly interact within the polymeric network and are no longer available for interactions with water molecules from the outer environment.

COMPARATIVE EXAMPLE C2 AND EXAMPLE 5

The same procedure as in example 1 is used, but substituting the BPA30EODMA oligomer for a urethane diacrylate oligomer CN965 from CRAY VALLEY Corporation. As a comparison, said urethane diacrylate has been polymerized in the absence of acrylic acid. The compositions and results are given in table II hereinafter: TABLE II C2 EX5 Polymerizable composition (liquid) Urethane acrylate (CN 965) 100 60 AA 0 40 Release agent 0 0.5 UV absorber 0 0 Photopolymerization primer 0.1 0.1 Solid polymerized material n_(e) (25° C.) 1.4922 1.5031 ν_(e) (25° C.) 55.2 54.5 Density — 1.23 E′ at 25° C. (MPa) — 1500 E′ at 100° C. (MPa) — 180 Tg (° C.) −30 125

COMPARATIVE EXAMPLE C3 AND EXAMPLES 67 AND 8

Example 1 is repeated by substituting BPA30EODMA for PPG 400 DMA in various proportions. The compositions and results are given in table III hereinafter. TABLE III C3 EX6 EX7 EX8 Polymerizable composition (liquid) PPG400DMA (%) 100 80 70 40 AMA (%) — 20 30 60 Release agent (%) 0 0 0 0.1 UV absorber (%) 0 0 0 0 Photopolymerization primer³ (%) 0.1 0.1 0.1 0.1 n_(D) (25° C.) 1.450 1.44 1.45 1.45 Density 1.01 1.01 1.01 1.02 Polymerized material (solid) n_(e) (25° C.) 1.48 1.492 1.494 — ν_(e) (25° C.) 45 57 55 — E′ at 25° C. (MPa) — 1,930 — — E′ at 100° C. (MPa) — 210 — — Water uptake at 25° C. 0.15 0.13 — 0.13 Tg 20 107 — —

The results show that stiffening through methacrylic acid occurs even at low methacrylic acid rates (20%) and that, on the other hand, the presence of propoxy groups allows to reach extremely low water uptake rates.

COMPARATIVE EXAMPLE C4 AND EXAMPLES 9 TO 11

The same procedure as that previously implemented is carried out, but using for component A a blend of BPA30EODMA and PPG 400 DMA oligomers.

The compositions as well as the obtained results are given in table IV hereinafter. TABLE IV C4 EX9 EX10 EX11 Polymerizable composition (liquid) PPG 400 DMA 50 40 30 25 BPA 30EODMA (%) 50 40 30 25 AMA — 20 40 50 Release agent (%) 0 0 0 0.1 UV absorber (%) 0 0 0 0 Photopolymerization 0.1 0.1 0.1 0.1 primer (%) n_(D) (25° C.) 1.471 1.465 1.458 1.453 Density 1.07 1.05 1.05 1.04 Polymerized material (solid) n_(e) (25° C.) — 1.503 — — ν_(e) (25° C.) — 52 — — E′ at 25° C. (MPa) — — 1,990 3,900 E′ at 100° C. (MPa) — — 440 1,600 Tg (° C.) <20 — 147 163

COMPARATIVE EXAMPLE C5 AND EXAMPLES 12 AND 13

The same procedure as used previously is implemented but using for component A a mixture of BPA30EODMA and dithiomethacrylate W oligomer made of a mixture of a first component represented by formula III (with n′ ranging from 1 to 10) and a second component represented by the following formula:

in a respective first component/second component mass ratio of 65/35. The compositions and results are shown in table V hereinafter. TABLE V C5 EX12 EX13 Polymerizable compositions (liquid) Dithiomethacrylate W (%) 50 40 30 BPA 30EODMA (%) 50 40 30 AMA — 20 40 Release agent (%) 0 0 0 UV absorber (%) 0 0 0 Photopolymerization primer(%) 0.1 0.1 0.1 n_(D) (25° C.) 1.528 1.508 1.490 Density 1.16 1.13 1.10 Polymerized material (solid) n_(e) (25° C.) 1.555 1.553 1.542 ν_(e) (25° C.) 42 44 48 E′ at 25° C. (MPa) — 916 3,840 E′ at 100° C. (MPa) — 85 1,140 Tg (° C.) <20 70 157

Stiffening by methacrylic acid is effective in all cases.

EXAMPLE 14

The above described examples are replicated using for component A a mixture of BPA30EODMA and mono-2-(methacryloyloxy)ethyl phthalate (MA phthlate) from ALDRICH Corporation.

The proportions of the components of the composition and the results are given in table VI. TABLE VI EX13 Polymerizable composition (liquid) BPA 30EODMA (%) 25 MA phthalate (%) 25 AMA (%) 50 Release agent (%) 0.1 UV absorber (%) 0 Photopolymerization primer (%) 0.1 n_(D) (25° C.) 1.4698 Density 1.09 Polymerized material (solid) n_(e) (25° C.) 1.5218 ν_(e) (25° C.) 44.4 E′ at 25° C. (MPa) 2,070 E′ at 100° C. (Mpa) 130 Tg (° C.) 155 Water uptake at 25° C./30 minutes (%) 1

EXAMPLE 15

Using the same procedure as previously described, spherical lenses have been manufactured with a −2 diopter power from the composition in example 2.

The resulting lenses are subjected to a shock resistance trial using an increasing energy ball drop (increasing the drop height up to break).

The results are shown in table VII hereinafter. TABLE VII BPA30EODMA + 50% AMA (EX2) Mean centre thickness of the tested lenses 1.1 Number of lenses broken with 520 g (ball) 6 mass Mean break energy >5,800 mJ

Such results show that the compositions according to the invention allow for high shock resistances to be obtained.

COMPARATIVE EXAMPLE C6

Example 2 from Patent Application WO 01/09205 is replicated in order to produce spherical lenses with a −2 dioptre power. Polymerizable composition Mass % SR 6440 P 52 *PLEX 6661-0 33 SR 423 A (isobornyl methacrylate from CRAY 15 VALLEY Corporation) *PLEX 6661-0 from CRAY VALLEY Corporation has the following formula:

with R₁₃ and R₁₄ representing independently from each other H or CH₃.

The resulting lenses, with a −2 dioptre power and a centre thickness of 1.1 mm, are subjected to a shock resistance trial, using the same protocol as in example 15.

Results Number of lenses broken with 520 g (ball) mass 31 Mean break energy 3,300 mJ 

1-24. (canceled)
 25. A radically polymerizable composition comprising: a first component A comprising at least an oligomer having at least two radically polymerizable functions, which, when polymerized, form a homopolymer of which has a glass transition temperature (T_(g)) lower than 50° C., such a component being able to result through polymerization in a (co)polymer having a glass transition temperature (T_(g)) equal to or lower than 50° C., said oligomer accounting for more than 15% of the total weight of the polymerizable monomers present in the composition; and a second component B comprising at least a (meth)acrylic monomer having at least one H link promoting group, such a (meth)acrylic monomer accounting for at least 15% of the total weight of the polymerizable monomers and oligomers present in the composition when such a monomer is a methacrylic monomer and at least 35% of the total weight of such polymerizable monomers and oligomers present in the composition when such a monomer is an acrylic monomer.
 26. The composition of claim 25, wherein the oligomer of the first component A is a difunctional oligomer.
 27. The composition of claim 26, wherein the oligomer is a di(meth)acrylate.
 28. The composition of claim 26, wherein the oligomer is a dimethacrylate.
 29. The composition of claim 25, wherein the oligomer has a number average molecular mass Mn ranging from 100 to 5,000 g.mol⁻¹.
 30. The composition of claim 29, wherein the oligomer has a number average molecular mass M_(n) ranging from 200 to 4000 g.mol⁻¹.
 31. The composition of claim 30, wherein the oligomer has a number average molecular mass M_(n) ranging from 300 to 2,000 g.mol⁻¹.
 32. The composition of claim 25, wherein the copolymer has a glass transition temperature (T_(g)) equal to or lower than 0° C.
 33. The composition of claim 32, wherein the copolymer has a glass transition temperature (T_(g)) ranging from −50° C. to −10° C.
 34. The composition of claim 25, wherein said oligomer of component A accounts for at least 20% of the total weight of polymerizable monomers present in the composition.
 35. The composition of claim 25, wherein the oligomer is poly(alkylene)glycol di(meth)acrylates, polyethoxy bisphenol-A dimethacrylates, dithio(meth)acrylates or urethane di(meth)acrylate.
 36. The composition of claim 25, wherein the oligomer is poly(ethyleneglycol) dimethacrylates or poly(propyleneglycol) dimethacrylates.
 37. The composition of claim 36, wherein the oligomer is a poly(propyleneglycol) dimethacrylate with a number average molecular mass of approximately 530 g.mol⁻¹.
 38. The composition of claim 25, wherein the compositions of the invention comprise additionally at least one other comonomer, being not an oligomer, comprising at least one radically polymerizable function.
 39. The composition of claim 38, wherein the radically polymerizable function is a (meth)acrylate function.
 40. The composition of claim 25, wherein the H link promoting (meth)acrylic monomer is a monofunctional monomer.
 41. The composition of claim 40, wherein the H link promoting (meth)acrylic monomer is acrylic acid, methacrylic acid, mono-2-(methacryloyloxy)ethyl succinate or mono-2-(methacryloyloxy)ethyl phthalate.
 42. The composition of claim 25, wherein the H link promoting (meth)acrylic monomer is represented by the formula:

wherein R represents H or CH₃, Z represents a single covalent link or a divalent spacer group and Z′ a H link promoting group.
 43. The composition of claim 42, wherein Z is a divalent hydrocarbon chain.
 44. The composition of claim 43, wherein the divalent hydrocarbon chain is interrupted by one or more heteroatom or by one or more groups as follows:

by one or more divalent groups of formula: —NH—CO—NH—; —NH—COO—; —NHCOS—; or —NHCSS—.
 45. The composition of claim 44, where the one or more heteroatom is O, S or N
 46. The composition of claim 43, wherein the hydrocarbon chain comprises from 1 to 10 carbon atoms.
 47. The composition of claim 46, wherein the hydrocarbon chain comprises from 1 to 6 carbon atoms.
 48. The composition of claim 42, wherein Z is a polyether, polyester, polyurethane, polyurea or polyurethane group.
 49. The composition of claim 42, wherein Z′ is: —COOH, —OH, —CONHR′, —NHCONHR″, —NHCOOR′″, —NHCOSR^(iv), or —NHR^(v) wherein R, R″, R′″, R^(iv) and R^(v) represent, independently from each other, H or a C₁-C₁₀ alkyl group or a C₆-C₁₀ aryl group.
 50. The composition of claim 49, wherein the alkyl group is an aliphatic or cycloaliphatic group.
 51. The composition of claim 50, wherein the aliphatic group is —CH₃.
 52. The composition of claim 42, wherein Z′ is the —COOH group.
 53. The composition of claim 42, wherein R is CH₃.
 54. The composition of claim 25, wherein it additionally comprises an effective amount of at least one thermal and/or photochemical polymerization primer.
 55. A product resulting from the thermal and/or photochemical polymerization of a composition comprising: a first component A comprising at least an oligomer having at least two radically polymerizable functions, which, when polymerized, form a homopolymer of which has a glass transition temperature (T_(g)) lower than 50° C., such a component being able to result through polymerization in a (co)polymer having a glass transition temperature (T_(g)) equal to or lower than 50° C., said oligomer accounting for more than 15% of the total weight of the polymerizable monomers present in the composition; and a second component B comprising at least a (meth)acrylic monomer having at least one H link promoting group, such a (meth)acrylic monomer accounting for at least 15% of the total weight of the polymerizable monomers and oligomers present in the composition when such a monomer is a methacrylic monomer and at least 35% of the total weight of such polymerizable monomers and oligomers present in the composition when such a monomer is an acrylic monomer.
 56. The product of claim 55, wherein it has an elastic modulus E′ at 100° C. of at least 40 MPa.
 57. The product of claim 56, wherein it has an elastic modulus E′ at 100° C. of at least 100 MPa.
 58. The product of claim 57, wherein it has an elastic modulus E′ at 100° C. of at least 120 MPa.
 59. The product of claim 55, further defined as an optical lens.
 60. The product of claim 55, further defined as an ophthalmic, finished or semi-finished, lens.
 61. The product of claim 55, wherein the copolymer has a glass transition temperature (T_(g)) equal to or lower than 0° C.
 62. The product of claim 61, wherein the copolymer has a glass transition temperature (T_(g)) ranging from −50° C. to −10° C.
 63. The product of claim 55, wherein said oligomer of component A accounting for at least 20% of the total weight of polymerizable monomers present in the composition. 